Hypodermic syringe



Feb. 16, 1932. H. H. Busi-1ER HYPODERMIC SYRINGE Filed Maron 12, 1950 A TTORNE Y.

Patented Feb. 16, 1932 UNITED STATES HERBERT H. BUSHER, F ST. PAUL, MINNESOTA HYPODERMIC SYRINGE applicati@ and marcan, 1930. serial No. 435,199.

My invention relates to hypodermic syringes in general and more particularly to a syringe of said kind involving a spring actuated plunger action to pierce the surface and project a needle into a fleshy area..

The main object is to provide a syrmge so operated as to eliminate the objectionable feature of hypodermic syringes as hitherto used' l" pushing the hypodermic needle by hand into the flesh. under the skin. In this device the needle is projected into the flesh by a very rapid projecting action of the cylinder to which the needle is attached, said action not kl only piercing the skin but projecting the needle intoithe flesh a predetermined distance by the same projecting action, after which the liquid to be injected is forced through the imbedded end of the needle and into the flesh. W1 My device is useful for any treatment of this kind but Was designed particularly for usc in diabetic cases where injection of insulin by patient himself is required at certain intervals and over extended periods of time.

The construction and use of my hypodermic syringe are hereinafter fully set forth, reference being had to the accompanying drawings in which preferred and modified forms of the device are illustrated.

In the drawings,-

Fig. 1 is a vertical elevation of my improved syringe in a preferred form `and set to project -its needle, the main casing in this instance being shown in longitudinal cross section to expose interior parts.

Fig. 2 is a right side elevation of Fig. 1 showing the needle projected from it.

Fig. 3 is a view corresponding to Fig. 1

but showing modified plunger means in which a standard type of hypodermic syringe is retained, this view showing also a modified type of releasing trigger.

Fig. 4 is a right side elevation of the upper part of the syringe-holding tube. shown 4" in Fig. 3 and omitting the pressure plunger. Referring to the drawings by reference numerals, 5 designates the plunger of a hypodermic syringe of a type well known in the medical arts, said plunger fitting slidably 5 and downwardly into the cylindrical connamely, the piercing of the skin andtainer 6 closed at its lower end except for a small passage 7 extending downwardly through a small neck 6N of the cylinder. On the outer extremity of said neck is the usual metal needle holder 8 from which the hypo- -ermic needle 9 extends -in concentric relation to the plunger and cylinder 6C is an integral collar at the upper end of cylinder 6 and 5H is a corresponding enlargement or head on the upper end of plunger 5. Thus far I have described the well known general type of hypodermic syringe now in common use and of which the needle is inserted into the flesh while. the device is held in inclined position after which the plunger is pressed inwardly to force medicine into the flesh through the needle. Such syringe may be used as a whole in the form of my device shown in Fig. 8, whereas in Figs. 1 and 2 the main cylinder 6 is formed at its lower end with an integral circular flange or enlargement 6F adapted to be reciprocated in a main glass tube or holder 10 tapered downwardly as at 10T and said tapered part having a central bore 11 guiding the needle 9. The upper end of the holder may be closed by a screw cap 12 as in Figs. 1 and 2, while in Fig. 3 the corresponding cap 12A is merely friction held or otherwise retained. Cap 12 is bored for the cylinder 6 to pass freely through it.

13 is a compression coil spring, about tube 6, and under compression between cap 12 and shoulder 6F of tube 6. 14 in Figs. 1 and 2 is a ring of soft material under head 6C of 85 plunger 6.

In Fig. 1 the cylinder 6 is retracted, or set, being drawn upwardly until the needle point is within the guide 11; 15 is a trigger pivotally mounted exteriorly of the tube as at 16 90 and having one end normally spring inwardly, as through an aperture 17 to engage under the lower end of tube 6, as shown, when the latter is up and spring 13 compressed. Pressure exerted on the free end of trigger 95 l5 will release the spring 13 which immediately plunges tube 6 downwardly and causing needle 9 to be projected out of the lower end of the device. The latter end should be pressed firmly against the skin, at a fieshy part and the abovt` described releasing and spring action will of course project the needle into the flesh with a rapid motion. 'lhe operator continues to press the device down after the needle has thus been inserted and operates the plunger member 5 to inject medicine as needed. The padding 14 serves as a shock absorber for tube (i when it strikes the top or cap 12.

In Fig. 2l a standard form of syringe is shown retained in a modified form of my device, the tube (i being removably retained in an upwardly opening cylindrical shell 18 having an opening 18A in its lower end through which the needle part is passed. This shell 18 has a circular flange 18l at its lower end adapted to be reciprocated loosely within an outer cylindrical shell 19 tapered at its lower end as 19T and provided in said latter part with a central needle guiding aperture 11A. The spring 13 acts to push cylinder 18 and its syringe member 6 downwardly, when released, the spring being under com ression between eap 12A and flange 18 i.

In this typey of my device a release trigger 15A pivoted at 16A is formed with an arm arranged to catch in an aperture 18A of cylinder 18. Pressure on the free end of the trigger releases the cylinder 18 which is plunged toward the lower end of shell 19, the needle being projected as previously described. 18S is an upwardly directed linger integral of cylinder 18 and bent to frictionally engage and retain the flange GC of cylinder 6. 20 is a suitable buffer in the lower part of cylinder to lessen the impact of plunger member 18 and the syringe when the spring action takes effect.

As previously stated, I have shown preferred embodiments of my device, its general principle being clearly disclosed. Other modifications of details may be made without departing from the scope and spirit of the invention. For example, other equivalenttrigger means may be used, the stroke of the plunger and its needle varied considerably, ete. In any form of the device it is stressed thatl the plunging action of the needle must be very quick, a sufficiently powerful spring being provided.

I claim:

In a hypodermic needle projector device of the class described, the combination of a main cylindrical body tapered at one end and havinY an outlet in said latter end, a secondary cy inder reciprocable within the main cylinder, means for removably retaining a hypodermic syringe within the latter cylinder with its needle extending toward the said outlet of the main c linder, spring means between sald two cy .inders and adapted to be compressed when retracting the inner cylinder from the outlet of the main cylinder, means for releasably holding the secondary cylinder in rel racted position, said hypodermic Syringe provided with a circular flanged shoulder normally exterior-ly of the secondary c linder, the hypodermic cylinder being provi ed with a plunger, and a yieldable friction device on said secondary cylinder, at its upper end, and adapted to removably engage said flange of the h podermic syringe, said yieldable friction evice comprising a leaf spring in position longitudinal of the secondary cylinder and project-ing beyond its upper end, said projected part comprising an inwardly opening hook adapted to frictionally engage said shoulder flange, as described.

In testimony whereof I affix my signature.

HERBERT H. BUSHER. 

